STUDY ON SYNTHETIC STOCHASTIC DAMAGE CONSTITUTIVE RELATION OF CONCRETE UNDER BIAXIAL COMPRESSION-TENSION

Most concrete structures are in a complex stress state．Considering the effect of the material composition and horizontal deformation of concrete,a biaxial compression-tension microscopic damage model is introduced,based on the uniaxial tensile microscopic spring-friction block model of concrete. In the light of the energy conservation during the process of damage failure,the synthetic stochastic damage constitutive equations of super high strength and high performance concrete (SHSHPC),high strength concrete (HSC) and normal concrete material subjected to biaxial compressive-stress are derived,and the sensitivity analysis results of the damage constitutive function are found. In order to testify the validity of the model,the calculated result is compared with the experiment data. It is shown that the model fits well with the experiment data.